Inspecting a Fuel Pressure Regulator on Mercruiser 7.4L MPI

Pellwm

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Sep 25, 2011
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I have been having Fuel pressure issues for awhile now, ran some electrical tests and found that im getting electric to the fuel pump but it doesn't kick on unless smacked around, so the pump is being changed.

Today my new fuel pump will be arriving and I will embark on the journey of replacing my old one. With this being said, and on the note of my issue being related to fuel pressure, I would also like to check my regulator while I have the old pump out since it is right there. The good ol' kill two birds with one stone approach.

I have been reading information on how to inspect it such as removing the hose from the top, turning the key to the ON position, and checking for any leaks. Just curious as to whether or not this is a good means of inspection or if there are other more reliable test? Thank you for any help.
 

Don S

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Re: Inspecting a Fuel Pressure Regulator on Mercruiser 7.4L MPI

I would say run the engine and check the fuel pressure and see if you have a problem or not. Without knowing exactly which EFI system your 7.4MPI has, it's really impossible to tell you how to check it. Do you have a serial number for your engine handy?
 

Pellwm

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Re: Inspecting a Fuel Pressure Regulator on Mercruiser 7.4L MPI

OL373782 is the serial number
 

Don S

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Re: Inspecting a Fuel Pressure Regulator on Mercruiser 7.4L MPI

Short of checking for fuel in the vacuum hose on the regulator, nothing to really check without running the engine.
 

Pellwm

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Re: Inspecting a Fuel Pressure Regulator on Mercruiser 7.4L MPI

Alright sounds good, fuel in the hose then its bad. Also, after the new pump is swapped in and I get it running, if pressure issues resume then I would suspect my pressure regulator being bad? Sorry for bombarding with the questions, I just want to be on top of this entire situation and get it fixed as the fuel system regulates my fun on the water lol
 

Don S

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Re: Inspecting a Fuel Pressure Regulator on Mercruiser 7.4L MPI

Depends on the type of fuel pressure problems as to what causes it. Look in the manual, there are all sorts of fuel system checks.
 
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